Abstract

Prioritising weeds for control and deciding upon the type of control and its associated investment are fundamental to weed management planning. Risk analysis is central to this process, combining the activities of risk assessment, risk management and risk communication. Risk assessment methodology has a rich history, but management feasibility has typically been a secondary matter, dealt with separately or not at all. Determinants of management feasibility for weeds include the stage of invasion, weed biology, means of control and cost of weed control. Here, we describe a simple weed risk analytical screen that combines risk assessment with species traits that influence management feasibility. We consider stage of invasion, species biological/dispersal characteristics and plant community invasibility in a preliminary analysis of the risk posed by the non-native plant species on Christmas Island in the Indian Ocean. For each of 31 high-risk species considered to be ineradicable under existing funding constraints, we analyse the risk posed to two major plant communities: evergreen closed-canopy rainforest and semi-deciduous scrub forest. Weed risk ratings are combined with ratings for species-intrinsic feasibility of containment (based on a measure that combines time to reproduction with potential for long distance dispersal) to create preliminary rankings for containment specific to each community. These rankings will provide a key input for a more thorough analysis of containment feasibility – one that considers spatial distributions/landscape features, management aspects and the social environment. We propose a general non-symmetric relationship between weed risk and management feasibility, considering risk to be the dominant component of risk analysis. Therefore, in this analysis species are ranked according to their intrinsic containment feasibility within similar levels of risk to produce an initial prioritisation list for containment. Shade-tolerant weeds are of particular concern for the closed-canopy evergreen rainforest on Christmas Island, but a greater diversity of weeds is likely to invade the semi-deciduous scrub forest because of higher light availability. Nevertheless, future invasion of both communities will likely be conditioned by disturbance, both natural and anthropogenic. The plant communities of Christmas Island have undergone significant fragmentation because of clearing for phosphate mining and other purposes. With a substantial number of invasive plant species firmly established and having the potential to spread further, minimising future anthropogenic disturbance is paramount to reducing community invasibility and therefore conserving the island’s unique biodiversity.

Addeddate

2025-04-01 15:39:26

Bhl_virtual_titleid

210923

Bhl_virtual_volume

v.66 (2021)

Call number

10_3897_neobiota_66_67769

Call-number

10_3897_neobiota_66_67769

Foldoutcount

0

Genre

article

Identifier

weedriskanalyti66pane

Identifier-ark

ark:/13960/s2g0zrv34dh

Identifier-bib

10_3897_neobiota_66_67769

Identifier-doi

10.3897/neobiota.66.67769

Ocr

tesseract 5.3.0-6-g76ae

Ocr_detected_lang

en

Ocr_detected_lang_conf

1.0000

Ocr_detected_script

Latin

Ocr_detected_script_conf

1.0000

Ocr_module_version

0.0.21

Ocr_parameters

-l eng

Page_number_confidence

79

Page_number_module_version

1.0.5

Page_range

95-116

Pages

22

Pdf_degraded

invalid-jp2-headers

Pdf_module_version

0.0.25

Possible copyright status

In copyright. Digitized with the permission of the rights holder.

Ppi

300

Source

NeoBiota 66

Year

2021

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